The present invention relates to a field mounted measurement transmitter measuring a process variable representative of a process. More particularly, the invention relates to a manifold for use with a transmitter for coupling the transmitter to process fluid transmitting fluid pressure to a differential pressure sensing means.
It has been an industry standard practice to use a flange adaptor and valve manifold to couple process conduits to pressure transmitters. The manifold connects a process conduit carrying a pressurized fluid to the flanged surface on a pressure transmitter. Often times, an H-shaped manifold is used between the conduit and the transmitter flange. Typically, manifolds had an inlet surface for receiving a process fluid opposite an outlet surface connected to the transmitter. In other words, the inlet surface was parallel to the outlet surface. Furthermore, manifolds were used with additional flanges or adaptor plates to attach the transmitter or process conduit. These assemblies are large, heavy, take up space, and have a number of joints and connections which promotes leaking of the fluid, and do not provide flexibility in installation.
Additionally, certain transmitter applications have specific requirements during transmitter use placing demands on the manifold which must be satisfied. For example, in the natural gas industry measurement accuracy is vital and must be taken into consideration when installing a manifold. In the power industry, in process calibration is important, and must be considered when installing a manifold.
Co-planar manifolds (for example, U.S. Pat. No. 4,745,810), eliminate the need for a flange between the transmitter and the manifold. Some co-planar manifolds, however, require a flange.
There is a continuing need for a space-saving manifold used to couple pressure transmitters to process conduits which inhibits leaking and which permits flexibility and ease in installation and use.